The present invention relates to a device for loading needle boards of felting and structuring machines.
Felting machines are disposed for rendering more dense non-woven fabrics of fibers, said fabrics consisting of randomly placed fibers such as, e.g., felts (with and without carrier material), and, optionally, also for post-processing woven and knit fabrics. For this purpose, the felting machines comprise an essentially plane support that is provided with a large number of felting needles. This carrier is also referred to as a needle board. The felting needles are seated in appropriate openings or bores, whereby the needles' holding part is pressed into said openings or bores. The term “felting needle” used herein also comprises needles that are used for post-processing, e.g., for roughening or perforating knit or woven fabrics.
The insertion of the needles in a needle board, as well as the removal of said needles, is a tedious procedure that is frequently performed—in full or in part—by hand. If needles are worn or if the needles of a needle board need to be replaced for other reasons, the old needles must be removed from the needle board and the new needles must be inserted in the needle board. Therefore, in the past, attempts have been made to at least partially automate this process.
Document EP 07 002 360 describes the simultaneous insertion of a number of felting needles in a row of bores of a needle board, said needles being mounted, under tension, parallel to each other at a prespecified distance by means of a multiple clamping chuck. To achieve this, a filling device is provided, said filling device individually providing—with the aid of two parallel-arranged worm conveyors—felting needles from a supply and at a proper distance corresponding to the division of the needle board, so that the needles can be grasped in groups by the multiple clamping chuck and be simultaneously set into the needle board.
Although the described device allows a considerable simplification of the loading process, a need for improvement is indicated. For example needles mounted in the multiple clamping chuck may somewhat deviate from the desired parallel alignment. The reason for this may be that the needles have been gripped not in exact parallel alignment by the multiple clamping chuck or that the needles are slightly curved. As a result of this, deviations regarding the position of individual needle tips may occur within a plane defined by the mounted needles as well as perpendicularly to said plane.
Inasmuch as the needle board bores are very close together, even a minimal positioning error prevents the insertion of a needle in its associate bore. If only a single needle is aligned wrongly, this may prevent the entire group of the needles mounted in the multiple clamping chuck from being inserted together. In order to trouble-shoot this error, manual intervention is necessary, for example, in order to manually align the affected needles or insert them into the needle board. Such complex post-processing delays the loading operation.
Accordingly, it is the object of the invention to enable a fast and reliable insertion of needle groups in a needle board.